The primary objective of the activities proposed in this application is to provide optical coherence tomography (OCT) Reading Center support to the Comparison of Age Related Macular Degeneration Treatment trial (CATT) during the conclusion of the CATT randomized clinical trial phase, and for the subsequent 3-year follow-up phase. The long term goals of this project, that will be accomplished through conduct of CATT are 1) to identify by OCT those eyes that are most likely to benefit from treatment in eyes with AMD, 2) to determine by OCT when treatment is effective or re-treatment is required and 3) to standardize OCT protocols and grading methods in eyes with AMD. 4) To determine OCT parameters that reflect long-term safety and efficacy of AMD treatment as administered in CATT. The primary objective will be accomplished through the following specific aims: SPECIFIC AIM 1: Provide the infrastructure to process OCT images that will be submitted by CATT study sites to the CATT OCT Reading Center during the remainder of the randomized clinical trial and follow-up phase SPECIFIC AIM 2: Certify and train CATT study personnel during the remainder of the randomized clinical trial and follow-up phase. SPECIFIC AIM 3: Provide Reliable, Timely, Reproducible, and Systematic Grading of Submitted OCT Material during the remainder of the clinical trial and follow-up phase. To achieve these aims, The OCT Reading Center will use a custom, stand-alone web-based system that we have developed to establish and implement secure methods for electronic time-domain and spectral-domain OCT data submission from the CATT clinical study sites to the CATT OCT Reading Center, and to store and back-up submitted data. We will use secure methods to transmit data from the OCT Reading Center to the Coordinating Center. We will develop custom software to quantify retinal and sub-retinal lesion area to monitor thickness changes over time. The Reading Center will also implement materials and methods for reader, OCT technician, clinical coordinator and ophthalmologist certification training, and will support study goals as an image resource for recruitment, Study Group meetings, presentations and publications. RELEVANCE (See instructions);the funds requested in this application will allow successful completion of the randomized clinical trial phase of CATT, and will provide critical safety and efficacy information during the follow-up phase. Results from this trial, which will affect hundreds of thousands of patients with neovascular age-related macular degeneration, will provide the basis for doctors and patients to choose between two different drugs and treatment mains Depending on the results. Medicare could save more than $1 billion per year.